BDA wrote:Reduce your portion sizes to help you reduce and maintain a healthy weight. A portion is: • a fist size of carbohydrate • a palm size of meat/fish or poultry • two handfuls of vegetables or salad • a cupped-handful of fruit • top of your thumb size of oil or fat spread.
https://www.bda.uk.com/foodfacts/diabetestype2.pdf
A fist size of carbs a thumb size of oil and this is evidence based bullshit